Enclosing another companies ads in your mailings/drop offs indirectly says that you are referring that company.
I referred one company for a few years that provided WONDERFUL service. Then he got too busy and got backed up and service dropped. I got complaints from my customers about it-why are you busting my chops about it? So now whenever I refer someone, I always say "I can't guarantee his work, he has done great work in the past, I don't know what he will do in the future, the only work I can guarantee is my own because I know it will be done correctly and professionally".
Obama is so bad, Kenyans are accusing him of being born in the USA.